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Ricardoco
13-11-2012, 06:01 PM
Ive looked at Building a power supply but "NO", I have no time, and No inclenation to build one so, Im looking to buy a power supply to run 4 x nema23 4nm motors on the front of 4 x MA860H drivers.

The Drivers spec:-
2MA860H Features:
- High performance, cost-effective
- Supply voltage up to DC(24-110V) AC(50-80V)
- Output current up to 7.2A
- Self-adjustment technology
- Pure-sinusoidal current control technology
- Pulse input frequency up to 200 KHz
- TTL compatible and optically isolated input
- Automatic idle-current reduction
- 15 selectable resolutions in decimal and binary, up to 12,800 steps/rev
- Suitable for 2-phase motors
- Support PUL/DIR and CW/CCW modes
- Short-voltage, over-voltage, over-current protections



Any sources or suggestions would be magic.

Rick

jonnydeen
13-11-2012, 06:38 PM
since the drivers support ac why not just wire them up to a transformer, its not exactly building a power supply


Toroidal Transformer 625va 0 55v 0 55v (http://www.rapidonline.com/Electrical-Power/Toroidal-Transformer-625va-0-55v-0-55v-88-3845)
this 625VA toroidal would provide 55VAC @11.4A

they also have 800VA & 1000VA ones available (1000VA giving 18.2A)

btw im not exactly an electronics guru so hopefully one of the more knowledgeable members can chime in

Ricardoco
13-11-2012, 09:38 PM
since the drivers support ac why not just wire them up to a transformer, its not exactly building a power supply


Toroidal Transformer 625va 0 55v 0 55v (http://www.rapidonline.com/Electrical-Power/Toroidal-Transformer-625va-0-55v-0-55v-88-3845)
this 625VA toroidal would provide 55VAC @11.4A

they also have 800VA & 1000VA ones available (1000VA giving 18.2A)

btw im not exactly an electronics guru so hopefully one of the more knowledgeable members can chime in
Hi, well jonathan did hint at a similar idea and i did look for the diagram that i had heard was here but to no avail, but an unregulated power supply just flies in the face of what my brain tells me, S0 i just thought there must be an off the shelf solution, but from the lack of responses it appears Jazz is not the only one being silent here tonight :concern:

Mind you not sure about the "Normally Despatched" "1-2 Months bit on the link you sent me lol

Rick

martin54
13-11-2012, 09:51 PM
Rick, I'm not an expert but this may help, Taken from the leadshine AM882 driver manual.


Both regulated and unregulated power supplies can be used to supply the drive. However,
unregulated power supplies are preferred due to their ability to withstand current surge. If regulated
power supplies (such as most switching supplies.) are indeed used, it is important to have large
current output rating to avoid problems like current clamp, for example using 4A supply for 3A
motor-drive operation. On the other hand, if unregulated supply is used, one may use a power supply
of lower current rating than that of motor (typically 50%~70% of motor current). The reason is that
the drive draws current from the power supply capacitor of the unregulated supply only during the
ON duration of the PWM cycle, but not during the OFF duration. Therefore, the average current
withdrawn from power supply is considerably less than motor current. For example, two 3A motors
can be well supplied by one power supply of 4A rating

Ricardoco
13-11-2012, 10:15 PM
Rick, I'm not an expert but this may help, Taken from the leadshine AM882 driver manual.


Both regulated and unregulated power supplies can be used to supply the drive. However,
unregulated power supplies are preferred due to their ability to withstand current surge. If regulated
power supplies (such as most switching supplies.) are indeed used, it is important to have large
current output rating to avoid problems like current clamp, for example using 4A supply for 3A
motor-drive operation. On the other hand, if unregulated supply is used, one may use a power supply
of lower current rating than that of motor (typically 50%~70% of motor current). The reason is that
the drive draws current from the power supply capacitor of the unregulated supply only during the
ON duration of the PWM cycle, but not during the OFF duration. Therefore, the average current
withdrawn from power supply is considerably less than motor current. For example, two 3A motors
can be well supplied by one power supply of 4A rating


That sorts that out then, So where can i get a nice large High current terroidal from then... Soon LOL the trouble is ive now got to get caps, wire, case, switch, blah blah blah.. But hey-ho i suppose..

Regards Rick

Jonathan
13-11-2012, 10:36 PM
I've got a spare one and the rest of the bits...will contact you about it.

This is the diagram I sent to Ricardoco in case anyone else wants it:
Untitled Page (http://www.arceurotrade.co.uk/projects/psu/index.html)

martin54
13-11-2012, 10:51 PM
Rick Jazz emailed me all the stuff for the transformer & the control box. It's on the other computer but will sort it out & send it to you tomorrow.

Ricardoco
14-11-2012, 12:21 AM
Rick Jazz emailed me all the stuff for the transformer & the control box. It's on the other computer but will sort it out & send it to you tomorrow.Cheers Martin..


Rick

wilfy
14-11-2012, 12:58 AM
I've got a spare one and the rest of the bits...will contact you about it.

This is the diagram I sent to Ricardoco in case anyone else wants it:
Untitled Page (http://www.arceurotrade.co.uk/projects/psu/index.html)


thanks for that link jonathan, i'm acctually still no wiser, dunno how everyone else feels... i think my brain has stopped working recently :/

Jonathan
14-11-2012, 01:23 AM
i think my brain has stopped working recently :/

Doubt I can help then ;)

Is there something specific you're not sure about?

wilfy
14-11-2012, 01:32 AM
i think if i look at it 2moro with a fresh head it'll be better.. but out of interest

with Best Selling! Wantai Stepper Motor Driver DQ860MA 80V 7.8A 256Micro CNC Router Mill Cut Laser Engraving Grind Foam-in Motor Driver from Industry & Business on Aliexpress.com (http://www.aliexpress.com/item/Stepper-Motoe-Driver-DQ860MA-80VDC-7-8A-256-replacing-MD882-Laser-Mill/560903752.html?cn=null&PID=5449378&tp1=skim20518X781349Xf12d616623e404a07c7e761e2a945 70d&tracelog=datafeeds&src=ale&URL=http%3A%2F%2Fwww.aliexpress.com%2Fitem%2FStepp er-Motoe-Driver-DQ860MA-80VDC-7-8A-256-replacing-MD882-Laser-Mill%2F560903752.html&cv=10887173&af=cj_5449378&vd=30&cn=null&PID=5449378&tp1=skim20518X781349Xb10e8c5339441fb5c8c0c33c6d162 004&tracelog=datafeeds&src=ale&URL=http%3A%2F%2Fwww.aliexpress.com%2Fitem%2FStepp er-Motoe-Driver-DQ860MA-80VDC-7-8A-256-replacing-MD882-Laser-Mill%2F560903752.html%3Fcn%3Dnull%26PID%3D5449378% 26tp1%3Dskim20518X781349Xf12d616623e404a07c7e761e2 a94570d%26tracelog%3Ddatafeeds%26src%3Dale%26URL%3 Dhttp%253A%252F%252Fwww.aliexpress.com%252Fitem%25 2FStepper-Motoe-Driver-DQ860MA-80VDC-7-8A-256-replacing-MD882-Laser-Mill%252F560903752.html%26cv%3D10887173%26af%3Dcj_ 5449378%26vd%3D30&cv=10887173&af=cj_5449378&vd=30)
as my driver and Nema23 Stepper Motor 3.1Nm x 3 (http://www.cnc4you.co.uk/index.php?route=product/product&path=83_84&product_id=66) as motors where do i fall in to that table?

Jonathan
14-11-2012, 01:50 AM
Those drivers will accept up to 80V and the motors are fine with that, so you can use a 50V transformer since when rectified that will get approximately 50*1.41-1.1=69.6V. A 500VA transformer would be ideal for 3 of those motors.

Ricardoco
14-11-2012, 02:54 AM
Ok I think this is the kiddy....

Standard Range Toroidal Transformers: CM2500450: 2500VA 230v to 4x50v (http://www.airlinktransformers.com/chassis_mounting_toroidal_transformers_standard_ra nge/3-CM2500450.html)

But will it fit the bill????



Rick

Jonathan
14-11-2012, 11:56 AM
:playful: How many machines are you planning on running?! That transformer is rated for 2500VA, so since 625VA is suitable for 4 motors, it could power 16!

From that site this one would be the best option:
Standard Range Toroidal Transformers: CM0625225: 625VA 230v to 2x25v (http://www.airlinktransformers.com/chassis_mounting_toroidal_transformers_standard_ra nge/3-CM0625225.html)
If you're planning on adding a 4th axis then the 750VA isn't much more and would allow you to do that. It's better to get the 2x25V transformer rather and put the windings in series rather than 50V and put them in parallel since if the secondaries are in parallel some current will flow between them (and not into the load) due to manufacturing variations, which could be harmful if significant. It's not very likely though. Another option if you do have to use a 50V transformer is to not put them in parallel and keep 2 seperate circuits with 2 drivers on each.

When you include postage and VAT this one is cheaper than airlink:
Toroidal Transformer 625va 0 50v 0 50v (http://www.rapidonline.com/Electrical-Power/Toroidal-Transformer-625va-0-50v-0-50v-88-3844)

Ricardoco
14-11-2012, 03:26 PM
:playful: How many machines are you planning on running?! That transformer is rated for 2500VA, so since 625VA is suitable for 4 motors, it could power 16!

From that site this one would be the best option:
Standard Range Toroidal Transformers: CM0625225: 625VA 230v to 2x25v (http://www.airlinktransformers.com/chassis_mounting_toroidal_transformers_standard_ra nge/3-CM0625225.html)
If you're planning on adding a 4th axis then the 750VA isn't much more and would allow you to do that. It's better to get the 2x25V transformer rather and put the windings in series rather than 50V and put them in parallel since if the secondaries are in parallel some current will flow between them (and not into the load) due to manufacturing variations, which could be harmful if significant. It's not very likely though. Another option if you do have to use a 50V transformer is to not put them in parallel and keep 2 seperate circuits with 2 drivers on each.

When you include postage and VAT this one is cheaper than airlink:
Toroidal Transformer 625va 0 50v 0 50v (http://www.rapidonline.com/Electrical-Power/Toroidal-Transformer-625va-0-50v-0-50v-88-3844)

Ok i figure if i must build a supply then i would really build one, i will be running other things requiring voltages less than 50v so this should cover the lot.

When i said i was going to do a "Big special" machine that is exactly what i meant.
Although i am using 4 steppers in the design that will only be providing me with 3 Axis, this machine will be having a 4th with quite a few other gadgets, i was going to go for Din rail supplies so i could add more as and when i needed them, but it is very much easier to just add a din supply that build another power supply.

So now i have opted to go down this road ive got to build in for the other stuff i will be fitting... Admittedly 2500va is a lot but i do like the 4x50v besides which its going to cost me more than that just to have the frame powder coated, as you may be becoming aware im building this thing for keeps...I may get a tad smaller transformer Ive got to do the math first.



Rick

Ricardoco
15-11-2012, 02:16 PM
ok I decided on going for this one: Standard Range Toroidal Transformers: CM1200171: 1200VA 230v to 120v (http://www.airlinktransformers.com/chassis_mounting_toroidal_transformers_standard_ra nge/3-CM1200171.html)

its not as big as the other one but then i Bought two!!

I think they are adequate for the job at hand


Rick

Jonathan
15-11-2012, 04:42 PM
i will be running other things requiring voltages less than 50v so this should cover the lot.

Then you should use the right size (750VA for 5 motors) transformer for the motors and get transformer(s) with lower voltage windings to power the lower voltage appliances, otherwise you've got to somehow drop the voltage further which is complicated to with any efficiency.


ok I decided on going for this one: Standard Range Toroidal Transformers: CM1200171: 1200VA 230v to 120v


Er, I hope not as that has a 120V secondary not 50V or 25+25V which is what you need for the motors.



its not as big as the other one but then i Bought two!!


So you'll have about 1.65kW surplus after powering the stepper motors - must be planning some pretty serious optional extras to use that much. Perhaps the machine is going to make tea...

Ricardoco
15-11-2012, 05:51 PM
Er, I hope not as that has a 120V secondary not 50V or 25+25V which is what you need for the motors.





So you'll have about 1.65kW surplus after powering the stepper motors - must be planning some pretty serious optional extras to use that much. Perhaps the machine is going to make tea...

Erm Not Sure what happened there here is the actual ones i have bought...

CM1200424 - Standard Range Toroidal Transformers
Product Description: 1200VA 230v to 4x24v

Is that better???


Rick

Jonathan
15-11-2012, 06:01 PM
Yes that's better, still seems OTT though. 4x25v would have been slightly better, but it's not a big deal.

With that transformer you will be able to get multiples of 35V, so 70V for the motors and 35V for other things. What voltage do the other things require?

Ricardoco
15-11-2012, 09:36 PM
Yes that's better, still seems OTT though. 4x25v would have been slightly better, but it's not a big deal.

With that transformer you will be able to get multiples of 35V, so 70V for the motors and 35V for other things. What voltage do the other things require?

The other things range from 12v to 32v but the contactors can be what ever i want when i order them.

Jonathan
16-11-2012, 12:05 AM
The other things range from 12v to 32v but the contactors can be what ever i want when i order them.

Presumably the contactors are just to switch these other things on and off?
The absolute minimum you can get from the transformer you have bought is by using one 24v winding, which when rectified will give 24*2^0.5-1.1=32.8V which is clearly above 32V so probably not much use. Also the tolerance on the mains voltage (230V +10% - 6%) means that it could be up to 32.8*1.1=36.1V.

How much power do these other things need? Can you provide a list of voltage and current or power that each device uses so we can work out the best transformer? It sounds like you'd be much better off with a separate transformer, perhaps 16V.

Ricardoco
16-11-2012, 12:18 AM
Presumably the contactors are just to switch these other things on and off?
The absolute minimum you can get from the transformer you have bought is by using one 24v winding, which when rectified will give 24*2^0.5-1.1=32.8V which is clearly above 32V so probably not much use. Also the tolerance on the mains voltage (230V +10% - 6%) means that it could be up to 32.8*1.1=36.1V.

How much power do these other things need? Can you provide a list of voltage and current or power that each device uses so we can work out the best transformer? It sounds like you'd be much better off with a separate transformer, perhaps 16V. If i was comming out and used non regulated that would be a problem but i will build a circuit to give me all the voltages i will ever need. Besides which they are on their way to me this moment.

rick

Jonathan
16-11-2012, 12:27 AM
If i was comming out and used non regulated that would be a problem but i will build a circuit to give me all the voltages i will ever need. Besides

The problem is unless it's less than a couple of amps it's hard to regulate the voltage, since linear regulators are extremely inefficient so you can only use them for quite small currents, SMPS's are quite difficult to design and adding more transformers is rather illogical, so I'll be interested to see how you plan to change the voltage. Also if the other appliances only use a small amount of current (making it reasonable to use linear regulators), then the transformers are probably several times bigger than they need to be.

Ricardoco
16-11-2012, 01:05 AM
The problem is unless it's less than a couple of amps it's hard to regulate the voltage, since linear regulators are extremely inefficient so you can only use them for quite small currents, SMPS's are quite difficult to design and adding more transformers is rather illogical, so I'll be interested to see how you plan to change the voltage. Also if the other appliances only use a small amount of current (making it reasonable to use linear regulators), then the transformers are probably several times bigger than they need to be. So you really think that they will be too much for 5 steppers and a few low amp (Less than 5A) power supplies providing 12V 18V 24V and maybe even 36v. I will be using circuits based on LM317's (or equiv) driving 2n3055s...

Rick

Ricardoco
16-11-2012, 01:28 AM
Jonathan, Check your mail..

Jonathan
16-11-2012, 01:50 AM
So you really think that they will be too much for 5 steppers

There's nothing wrong with having too much power available - it's just generally doesn't make economic sense.


and a few low amp (Less than 5A) power supplies providing 12V 18V 24V and maybe even 36v. I will be using circuits based on LM317's (or equiv) driving 2n3055s...

Earlier you said you didn't want to make a power supply when it was just a transformer, rectifier and capacitor, but now you're suggesting a lot more components to get what you could have made for less money by just using the correct voltage transformers. For the 12V and 24V you could have used a transformer with two 9V secondaries, which would be much cheaper, easier and more compact. 36V can be had from the stepper motor transformer. 18V from a 12V transformer.

A linear PSU made with LM317's and 2n3055 transistors may work, but the power it dissipates will be huge. Say you're using 12V at 5A - the voltage across the transistor Collector-Emitter junction is 32.8-12=20.8V. At 5 amps that means your transistor has to dissipate 20.8*5=104W. The absolute maximum rating for that transistor is 115W (TIP3055 only 90W), but that's not enough since as the transistor junction to case thermal resistance is thermal resistance is 1.5C/W, even with a perfect heatsink it can only dissipate (150-25)/1.5=83W at 25C ambient. Add to that another few of these circuits and your control box is going to turn into an oven unless you're planning on linking it to the spindle water cooling!

This concept is workable if the power dissipation is less, which is likely to be the case for the 24V output, but it seems a lot of hassle and expense when you could have just got a transformer, or two, with the right voltages and VA rating to start with. The only reason I'd do it is if the devices you're powering need the high power quality (low ripple in particular) delivered by a linear supply, which seems unlikely.


Jonathan, Check your mail..

I have...

Ricardoco
16-11-2012, 02:35 AM
There's nothing wrong with having too much power available - it's just generally doesn't make economic sense.



Earlier you said you didn't want to make a power supply when it was just a transformer, rectifier and capacitor, but now you're suggesting a lot more components to get what you could have made for less money by just using the correct voltage transformers. For the 12V and 24V you could have used a transformer with two 9V secondaries, which would be much cheaper, easier and more compact. 36V can be had from the stepper motor transformer. 18V from a 12V transformer.

A linear PSU made with LM317's and 2n3055 transistors may work, but the power it dissipates will be huge. Say you're using 12V at 5A - the voltage across the transistor Collector-Emitter junction is 32.8-12=20.8V. At 5 amps that means your transistor has to dissipate 20.8*5=104W. The absolute maximum rating for that transistor is 115W (TIP3055 only 90W), but that's not enough since as the transistor junction to case thermal resistance is thermal resistance is 1.5C/W, even with a perfect heatsink it can only dissipate (150-25)/1.5=83W at 25C ambient. Add to that another few of these circuits and your control box is going to turn into an oven unless you're planning on linking it to the spindle water cooling!

This concept is workable if the power dissipation is less, which is likely to be the case for the 24V output, but it seems a lot of hassle and expense when you could have just got a transformer, or two, with the right voltages and VA rating to start with. The only reason I'd do it is if the devices you're powering need the high power quality (low ripple in particular) delivered by a linear supply, which seems unlikely.



I have...


OK i did ask about off the shelf din solutions giving me the ability to simply add extra units as and when i needed them and it seemed that opinion was against that, so as this isnt going to just look like a box of spagetti like a lot of projects i see turn out, i had to factor in not only what i want now but also guess what i may need in the future, the last thing i want is to keep stripping the damn thing down to do mods. I want to wire the Box, take into consideration what i need at the time of building and build it, and if that includes a 6" fan or two for cooling then so be it, shut the door on the cabinet and dont open it till the warning light and buzzer comes on, Yes there may be a heat dissaption requirement by the multiple 2n3055's but it wont be the first successfull supply ive build by any means, i think i build my first one when i was 12 and although that is long since been stripped for bits my current dual 0-30vdc supply was built by me 25yrs since, and im still very happy with it, although im always happy to try new ideas.

So You know what i have get your thinking head on and show me a better circuit solution. That would be magic


Rick

samsagaz
22-11-2012, 03:53 AM
What wrong using directly an AC Source? for example use directly an transformer 220AC to 110AC?

Is better to use DC Instead AC?

Thanks

Jonathan
22-11-2012, 02:28 PM
OK i did ask about off the shelf din solutions giving me the ability to simply add extra units as and when i needed them and it seemed that opinion was against that

Yes, since at the time there was no mention of powering other things. Still, I wouldn't use them for powering the other things or stepper motors since they're so much more expensive.


if that includes a 6" fan or two for cooling

My point is that may not be enough - if the transistors aren't rated for the power dissipation required it doesn't matter how big the fans are, it's not going to work (unless you split the power between multiple transistors).


So You know what i have

No, I don't know since you've not said exactly what current each of the other devices require and without that there's no point in further speculation.


What wrong using directly an AC Source? for example use directly an transformer 220AC to 110AC?

Is better to use DC Instead AC?

This thread started by discussing which PSU is most suitable for powering stepper motor drivers, which in general run from a DC source so you have to rectify the transformer output to obtain that.

Ricardoco
23-11-2012, 11:23 PM
Ok, Ive recieved My toroidal which is 4x24 1200VA so using a series arrangement i will have the 50-80vac I require for the Drivers/steppers i will also have 1 or 2 free windings at approx 24vac which is what the contactors require, I will be using an ATX power supply for the smaller relays and the indicator 3v LED's and 5v for the bob as i have one and its easy, im still waiting for the Enclosure which should be here in the week sometime, and the caps im sure i have beneath a few cob webs somewhere.

7439

Looks Like she will be getting that bigger coffee table she has been asking for. cos there wont be room on this one for the rest of the stuff by the end of the week...

Rick

Ricardoco
24-11-2012, 02:08 PM
Ok just got the multi meter on the Transformer so i know where im going, atnd im getting 26.76vac using a single winding and 53.6vac using two windings and 80.1vac using three, so if i use the calculations provided by Jonathan of X*1.41 -1.1 to show the rectified Voltage
I get:
36.55Vdc
74.48Vdc
111.84Vdc
Respectively
I will be Using the forth winding else where..

So there is a start

Rick

hoppo
29-01-2013, 07:13 PM
Just wanted to say thanks to you guys on this thread for helping me out with my power supply build. I managed to pull a good case out of the skip at work which I chopped and changed to suit. I used a 750KVA 0-25 0-25 transformer in the end in case I ever add a 4th axis. Wired the two secondaries in series and through a bridge rectifier and a couple of 80v rated capacitors. All working smoothly, giving a nice smooth DC output of circa 75v. I do still need to add a fuse on the output of the secondary, just waiting for the fuse holder to arrive from Farnell and It'll be complete. I've tried it with a couple of my DQ860MA drivers and all working very nicely indeed. Thanks again.

8072

Clive S
29-01-2013, 07:21 PM
Re the caps. 80V rated might be a bit low !! I would suggest at least 100V for safety.

hoppo
29-01-2013, 07:39 PM
Good advice, I did think it was a little close but I had them to hand, I'll get a couple rated at 100v to replace them eventually, thanks Clive.

Jonathan
29-01-2013, 07:56 PM
Good advice, I did think it was a little close but I had them to hand, I'll get a couple rated at 100v to replace them eventually

It is good advice. I also had some 80V capacitors to hand when I made mine, so that's what I used.

Clive S
30-01-2013, 10:36 AM
Yes I forgot to say if you have never seen one blow up, the mess they can make in unbelievable !!

i2i
30-01-2013, 11:39 AM
one suggestion, it may be a bit late, and i'm no electronic expert. Most systems i've converted have a transformer for the drives and a seperate one for the logic.
There must be a good reason for this as transformers are both heavy and take up valuable space.

m_c
30-01-2013, 06:37 PM
Seperate supplies is more a commercial controller thing. You want to be able to kill the movement without killing the controller, just like with Mach/LinuxCNC, you want to kill the machine without killing the computer.

Some will use a seperate supply for the break-out board, as the BOB needs power and it's easier/tidier than trying to get 5v from the computer.